Debt

The following table presents debt balances as of September 30, 2018, and December 31, 2017.



	September 30, 2018		December 31, 2017
$545.0 million Senior Secured Term Loan B (“Senior Secured Term Loan”) bearing interest at the greater of 0.75% or one-month LIBOR (2.26% at September 30, 2018), plus an applicable margin of 3.75% at September 30, 2018, expiring October 19, 2022	$	534,250	$	534,250
$300.0 million Incremental Term Loan (“Incremental Term Loan”) bearing interest at one-month LIBOR (2.26% at September 30, 2018), plus an applicable margin of 3.25% at September 30, 2018, expiring April 3, 2021	282,000		291,000
$143.0 million Senior Secured Revolver (“Senior Secured Revolver”) bearing interest at one-month LIBOR (2.26% at September 30, 2018), plus an applicable margin of 3.5% at September 30, 2018, expiring October 19, 2020	69,401		—
International lines of credit and other loans	7,584		3,315
Total	893,235		828,565
Less current maturities of long-term debt	31,726		17,283
Principal, net of current portion	861,509		811,282
Less unamortized debt issuance costs	17,989		20,477
Long-term debt, net of current portion	$	843,520	$	790,805

We capitalized interest costs amounting to $0.3 million and $0.2 million in the three months ended September 30, 2018 and 2017, respectively, and $0.8 million and $0.9 million in the nine months ended September 30, 2018 and 2017, respectively, related to construction in progress.

Collectively, our Senior Secured Term Loan, Incremental Term Loan, and Senior Secured Revolver comprise our credit facility. Principal available under the Senior Secured Revolver was $100.0 million as of September 30, 2018. Available principal may be restored to $143.0 million upon the achievement of certain requirements. Our credit facility is subject to certain financial covenants based on a consolidated net leverage ratio, as defined in the credit facility agreement. The financial covenants are effective when we have outstanding amounts drawn on our Senior Secured Revolver on the last day of any fiscal quarter and become more restrictive over time. We had a $69.4 million outstanding balance on the Senior Secured Revolver as of September 30, 2018, and we were in compliance with all covenants under our credit facility.

Second Lien Credit Agreement

In connection with the Paragon Medical acquisition, we, certain of our subsidiaries named therein, SunTrust Bank, as Administrative Agent, SunTrust Robinson Humphrey, Inc. as Lead Arranger and Bookrunner, and the lenders named therein entered into a Second Lien Credit Agreement (the “Second Lien Credit Agreement”) pursuant to which SunTrust and the other lenders extended to us a $200.0 million secured second lien term loan facility (the “Second Lien Facility”). We utilized the net proceeds from the Second Lien Facility, together with cash on hand, to pay the Paragon Medical purchase price and fees and expenses related to the acquisition. The Second Lien Facility was collateralized by all of our assets. The Second Lien Facility had an original maturity date of April 19, 2023, and bore interest at either (i) a base rate, plus an applicable margin, or (ii) the greater of the London Interbank Offered Rate (“LIBOR”) or 1.00%, plus an applicable margin. The initial applicable margin for all borrowings under the Second Lien Facility was 7.00% per annum with respect to base rate borrowings and 8.00% per annum with respect to LIBOR borrowings. We voluntarily prepaid in full the $200.0 million outstanding principal balance with proceeds from the sale of common shares on September 18, 2018. We paid a prepayment penalty of two percent, or $4.0 million, and wrote off $2.6 million of unamortized debt issuance costs.

On September 18, 2018, we issued 14.4 million common shares in a registered public offering. Net proceeds of approximately $217.3 million were used to repay the Second Lien Facility and a portion of the Senior Secured Revolver.

Amendment to Credit Facility

On May 7, 2018, we entered into an amendment to our existing credit facility to permit the Paragon Medical acquisition, to permit the Second Lien Credit Agreement, and to amend certain covenants. We paid $16.7 million of debt issuance costs related to the amendment. A total of $12.9 million is included in the “Loss on extinguishment of debt and write-off of debt issuance costs” line on the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss). The remaining $3.8 million is capitalized as a reduction of long-term debt.